


Sweet Betrayal.

by psyleedee



Category: Among Us (Video Game), Supernatural
Genre: Alternate Universe - Among Us (Video Game) Setting, Anal Fingering, Anal Sex, Ass Play, Barebacking, Bottom Castiel (Supernatural), Choking, Cock Slut Castiel (Supernatural), Come Inflation, Come Marking, Come as Lube, Crewmate Castiel, Dubious Consent, Gay Sex, Grinding, Horny Castiel (Supernatural), Impostor Dean Winchester, Large Cock, Love Bites, M/M, Marking, Monster Dean Winchester, Plot What Plot/Porn Without Plot, Porn, Rough Kissing, Rutting, Shameless Smut, Size Queen Castiel (Supernatural), Smut, Temporary Character Death., Tentacle Sex, Tentacles, Top Dean Winchester, Unsafe Sex, Wall Sex
Language: English
Status: Completed
Published: 2020-12-13
Updated: 2020-12-13
Packaged: 2021-03-10 21:02:23
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,345
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28053615
Author URL: https://archiveofourown.org/users/psyleedee/pseuds/psyleedee
Summary: Castiel is a Crewmate in the Skeld, simply trying to complete his tasks, but when the lights are down in Electrical, he has to face being alone in the room to fix them.The doors shut, he's locked inside, and somebody just vented. Oh, it's just Dean.Wait, what?
Relationships: Castiel/Dean Winchester
Comments: 14
Kudos: 180





	Sweet Betrayal.

**Author's Note:**

> lakka i love you to the moon and back for this prompt.

"Fix Lights."

The alarm blared through the Skeld, high-pitched and stinging, and Castiel glanced up, eyes roaming above over the ceiling. He was busy clearing the asteroids in Weapons, and he had another task in Electrical to calibrate the distributor, so he winded up clearing the asteroids, and made his way over to Electrical, where the lights needed to be fixed. With only three crewmates alive, out of which one had to be the Impostor, Castiel's nervousness grew as he neared Electrical. Somehow, the passage seemed empty—eerily empty, but he had no choice. The lights needed to be fixed.

Mustering as much courage as he could, he stepped into Electrical. He wasn't fond of the room, nor did he think anybody else was. It was the perfect spot for an Impostor to kill someone. Dark, quiet, murky, and full of strange corners where who knows what could be lurking. As he approached the light circulator, he realised however, that the room was empty. Breathing a sigh of relief, Castiel stepped up to the circulator to fix the lights, when at once, a loud clang rung behind him.

The moment he turned around however, his eyes went wide as he realized—

The doors. They were shut.

Frantic, scared for his life, Castiel ran towards the door, pounding his fists on the metal door as hard as he could, broken screams bouncing off the metal as he yelled out.

"Help— help— open up, please— hel—"

A sound. Another one. From the dark depths of the room. The sound of—

The vent.

Fear seized him and curled within his nerves as he gasped, and pressed his back against the door, waiting and watching, absolutely paralysed to his feet, as a shadow crept closer. Part of him knew there was no escape, no matter how much he prayed, the Impostor would have their way with him, but in his final moments, he could do nothing but hope the other crewmates would fight for justice to his body, and to the bodies of all his mates who died before him, and that good would triumph over evil.

"Hey, Blue."

Castiel's eyes snapped open at once, and before him, dressed in a tight, dark-green coloured space-suit was Dean. His green eyes studied Castiel with a strange, inscrutable expression, one Castiel knew held pity and pride, but even so, Castiel couldn't find it in himself to believe his own eyes.

This had to be a lie.

It couldn't be Green. After all, Castiel had trusted him. Every time Castiel had wanted to complete a task alone, Green, or perhaps Dean, had trailed him around, protected him, stood up for him in the discussions when anybody suspected Castiel, and Castiel in turn had stood up for Dean. There was no way Dean could have done it. Dean had been with Castiel every moment. How could he possibly have done such a cruel thing? How could he betray Castiel? After everything they shared, after their friendship, after Castiel had trusted Dean with his _life_?

It had to be a lie.

"Dean?" Castiel croaked out, shock dripping from his voice, and from a few feet away, came a dark, patronising chuckle.

"Yeah, it's me."

"B—but how? I _trusted_ you—"

"And I'm sorry, I really am." Bright green eyes gazed up at Castiel, and before Castiel could run, Dean had him pinned against the metal door, one hand gripping Castiel's narrow waist, and the other cradling Castiel's jaw as Dean stroked a thumb over his cheekbone. As if on instinct, Castiel felt his eyes flutter shut.

"No, it can't be you. It can't—" Castiel gasped, giving into Dean's warm touch.

"But it is. I can't tell you how much it hurts me to do this, Castiel, but I don't have a choice. And trust me, everything you've done for me, standing up for me in the discussions, helping me with an alibi, watching over me— I will never forget your compassion," Dean whispered, his breath hot and ghosting over Castiel's lips as he leaned in, his eyes fluttering shut as their faces inched closer, "I hope you can forgive me."

Dean brushed his lips against Castiel's in a tender, hesitant touch, simply testing for a moment, before diving in deep. Within Dean's arms, Castiel felt himself give in completely. He had no escape. He had no refuge. He was going to die here, Dean was going to kill him, but with the way Dean kissed him in his final moments, passionate, loving, delicate, it made Castiel feel, in the slightest at least— that the warmth he had shown Dean meant something. Even if he knew Dean would kill him, he knew also, that he would do it with much more affection than he did to the others. And somewhere inside Castiel, unfurled pride at having been Dean's exception, of having been the sole owner of Dean's affections.

Moans spilt past Castiel's lips as Dean's hands wandered up towards the zipper on the back of Castiel's space-suit, the other curling around Castiel's head to protect him from the metal door. Castiel curled his back into Dean's touch, feeling the zipper slide down, slow and tempting, and Dean pulled away from their kiss, instead diving into the depths of Castiel's neck. A whimper escaped Castiel's throat, and he felt himself squirm in Dean's arms with need and arousal. His cock grew heavier, and strained against the fabric of his suit, when at last, the zipper unraveled, and Castiel felt his suit fall open from the chest below. The musty air in the room kissed his skin, leaving goosebumps over his flesh as he let his head fall to the side to allow Dean to suck marks into his skin.

"Mh, _oh Dean_ —"

"Shh, be good for me, Blue," Dean whispered, before gripping Castiel by the waist and turning him around to slam his chest into the metal door. Castiel moaned, and pushed his clothed, taut, round ass out as invitation. At once, Dean's hands were pushing the suit down, tossing his backpack away, and letting the suit pool around Castiel's ankles. Naked and pressed against the cold metal door, Castiel let out a loud whine, bucking his hips backwards and grinding his ass against Dean's clothed, large, bulging erection. He rubbed his crack over the thick girth of Dean's cock, which could be felt through the thin fabric of the suit, and not soon after, Dean was hissing, large warm palms grabbing Castiel by the waist as he rubbed his cock over Castiel's naked ass.

"Need, need your cock—" Castiel gasped, but before he could let out another needy moan, something tickled against the back of his neck, and his eyes fluttered open. His palms were planted over the wall as he bent over for Dean, but the tickling still persisted. At last, he glanced back at Dean, only to find—

Dean's face had contorted. His eyes had gone pitch-black, and his seemingly harmless tongue had now erupted into a long, thick ribbed dark, moss-green tentacle which split at the tip like that of a snake.

Instead of fear, however, Castiel felt himself leak more pre-come at the tip of his cock, and arousal coursed through his veins at the thrill of being fucked by a monster.

A monster.

_"Hnggh—"_

Castiel's gasps and moans filled the air, paired with the sound of Dean growling at the back of his throat. His fingernails had grown sharper, his skin greener, and his body bulkier. It shadowed Castiel completely, and the feeling of having someone, or rather something, as big as Dean manhandle him, it spiked the arousal in his veins. His nippled perked and rubbed against the cold metal as Dean laved his tongue over Castiel's neck, lathering Castiel's skin with drool as Dean sucked large, purple marks into Castiel's skin.

The sound of fabric ripping drew Castiel's attention to it, and he glanced back to find Dean tearing through the cloth of his dark-green suit to free his cock from the confines of the fabric.

To call it a cock, however, was an understatement.

It was as large as a forearm, wide and thick, and the girth of it was ridged with thick, bursting veins. The tip was a rosy, flesh coloured, while the rest or the length had a faint green tinge to it. Hanging before Castiel's ass, Dean's cock was _huge_ , much larger than Castiel's own, and Castiel clenched his hole, wondering how it would feel to have a cock as large as Dean's sink into his stomach.

"Fuck," Castiel cursed, as he spread his legs apart, one hand working his own cock, the other holding onto the metal door, and presented his ass to Dean, who laid a sharp slap on it, tinging it a bright, stinging red.

"Tasty," Dean growled, his voice suddenly octaves deeper and grittier as he growled, and Castiel found himself unable to tear his eyes away from Dean's cock.

It leaked a large string of thick, white pre-come at the tip, and Dean gathered it across his fingers, only to spread his pre-come over Castiel's tight, pink puckered hole. Castiel hissed at the touch, letting his head fall forward, when at once, Dean's long, thick tentacled tongue snaked around Castiel's neck and squeezed it. A loud whimper felt past Castiel's lips as Dean choked him with his long, snake-like tongue, and yet, he found himself giving in and arching his back as Dean's fingers, simply two of them, thrusted into his tiny hole.

Pleasure washed over Castiel at having his hole stretched open and fingered, especially when Dean's fingers brushed against his prostate and he let out a loud moan. But the next moment, Dean pulled he fingers out, leaving Castiel's hole empty and twitching. Castiel gasped, and glanced behind, watching as Dean rubbed his large, monster cock against Castiel's hole, teasing the entrance but never pushing in.

"Dean," Castiel mewled, reaching back to pull his ass cheeks apart, allowing Dean a clearer view of his small, pink pucker which quivered in tune with Castiel's breaths.

"So delicious," Dean growled, the low timbre of his voice sending pleasure straight down to Castiel's gut.

 _Finally,_ Dean began to push.

And _god_ , it felt _ethereal_.

Castiel's hole _gaped_ around Dean's cock, opening up wide and big as Dean pushed the tip in, easing his way inside with his pre-come, but the moment the girth of it began sinking in, Castiel felt himself lose all semblance of self. His tongue hung over his lips, his eyes rolled to the back of his head, and drool ran down the side of his mouth as he grinned, completely out of it, feeling Dean's large, monstrous cock fill him.

His hole burned. It stung with every inch Dean pushed in, and Castiel had never more wanted to push something out as much as he wanted to suck it in, and that's precisely what he felt as Dean's cock continued sinking into him, no where near the end even though a solid minute had passed.

"S—so big," Castiel mumbled, as his mouth hung open, legs _trembling_ , body shaking and spasming with every inch of his beastly cock Dean thrusted deeper inside. The hand working at his own cock came to a pause as Castiel felt, after ages of going slow and tender, Dean had given up, and in one final attempt to fuck his giant cock into Castiel's hole, Dean snapped his hips forward.

A loud wail echoed through the room as Castiel's eyes widened, his jaw dropped, and his body curled into Dean's touch. His hole, his poor, tiny pink hole, now gaped around Dean's cock, and Castiel cried thick, fat tears when he felt Dean's cock bottom out inside him. Deep. So deep. Too deep. Absently, Castiel grazed a hand over his stomach, and found it bulging with Dean's fat cock plunged deep inside him.

 _"Ah— ah— ah—ah— mph—"_ Castiel broke into a string of moans as Dean groaned behind him, and after what felt like ages, began to move. In and out, in and out. The drag of his cock was so long Castiel felt his anal walls dilate and contract, only to swell open when Dean's cock plunged in.

Searing white pleasure bubbled through Castiel's gut, and he felt his cock twitch, before finally, the pressure in his gut erupted, and he came in thick, clear splatters all over the metal door.

Dean's thrusts only increased.

Faster and deeper.

It was unlike Castiel had ever felt before. It was as if he meant nothing to Dean but a hole to fuck and breed, and something about the feral, unhinged way Dean fucked into him, absolutely brutal and ruthless, it only had Castiel leaking from the tip of his soft cock as he slammed his fists against the metal door and let out loud, obscene moans, unable to breathe as Dean's tongue choked him.

"Coming," Dean growled into Castiel's ear, his monstrous, vicious voice sending a shiver running down Castiel's spine, and Castiel clenched down on Dean's cock, sucking him in deeper, until Dean slammed so deep, Castiel felt his gut rupture, and his chest crashed into the metal door.

Burning hot, thick semen flooded Castiel's ass, one load, two loads, three loads— it seemed unending as it filled Castiel's stomach.

They remained joint together for a few minutes, Dean's large, painful cock lodged inside Castiel's hole, but then he pulled out, and chasing after Dean's cock, came his thick, hot white semen, gushing out of Castiel's ruined, gaping hole. The come dripped down to the floor and dribbled down Castiel's thighs, but Dean swiped a hand through the mess, pushing and fingering his come back into Castiel's loose, wide hole.

Dean's tongue tightened around Castiel's neck, and he realised, in his hazy mind, this was it.

This time, he couldn't find it in himself to struggle against Dean.

In a split second, Castiel felt something in his neck crunch, and then, it was complete, pitch-black darkness.

* * *

_Defeat_.

* * *

_Waiting for host._

**Author's Note:**

> okay relax the ending isn't as sad as it sounds, alright? besides, they totally rejoined the game and impostor!cas killed dean but he also rode his dick in navigation first so :/


End file.
